A061431 a(n) = LCM of the n consecutive numbers n(n-1)/2 + 1, ..., n(n+1)/2.

1, 6, 60, 2520, 60060, 1627920, 124324200, 1694579040, 446626220040, 73706596563600, 177223661334720, 171986625946535400, 3290057629552053360, 551042196782556679200, 71028805196838414285360, 5709613258492889617872000, 20986612729658105596044778800

Offset

1,2

Links

Harvey P. Dale, Table of n, a(n) for n = 1..342

Example

a(1) = 1, a(2) = lcm(2,3) = 6, a(3) = lcm(4,5,6) = 60, etc.

Mathematica

LCM@@Range[#[[1]]+1, #[[2]]]&/@Partition[Accumulate[Range[0, 20]], 2, 1] (* Harvey P. Dale, Jul 30 2016 *)

Prog

(Magma) [Lcm([n*(n-1)/2 + 1.. n*(n+1)/2]): n in [1..30]]; // Vincenzo Librandi, Mar 18 2018
(PARI) a(n) = lcm([n*(n-1)/2 + 1..n*(n+1)/2]); \\ Michel Marcus, Mar 18 2018

Crossrefs

Sequence in context: A363789 A271682 A082681 * A261523 A318131 A202620

Adjacent sequences: A061428 A061429 A061430 * A061432 A061433 A061434

Keyword

nonn,easy

Author

Amarnath Murthy, May 03 2001

Extensions

More terms from John W. Layman, Oct 16 2001

More terms from Harvey P. Dale, Jul 30 2016

Status

approved